[Haematuria in children. I. Differential diagnosis of haematuria in childhood (author's transl)].

Haematuria in children is either of glomerular or nonglomerular origin. In the latter case intravenous urography should always be performed. A renal biopsy is indicated if unexplained haematuria persists for at least one year or if an unfavorable prognosis is indicated by the appearance of hypertension, significant proteinuria or persistently low levels of serum complement (C3). The importance of screening the families of haematuric patients is emphasized. More than half of our cases with persistent or intermittent haematuria undergoing renal biopsy showed no or only minimal glomerular changes. In other children with a similar clinical picture more severe histological lesions were detected. In any case the kidney tissue obtained by biopsy should be examined by immunofluorescence and by electron microscopy. One of the most frequent causes for persistent or intermittent haematuria during childhood is Berger's disease (IgA/IgG nephropathy).